I bought this plastic-welding tool that TikTok suggested. Did the algorithm get it right?

There's a lot inside the plastic welding kit!

There's a lot inside the plastic welding kit!

Adrian Kingsley-Hughes/ZDNET

The social media algorithms have clearly labeled me “Mr. Fix-It,” as my TikTok and Instagram feeds are swarming with mesmerizing videos of plastic welders in action.

Haven't caught one of these cool clips? Feast your eyes on this gem.

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The concept is simple yet brilliant: use these “welding wizards” to fuse tiny metal staples into the fractures of cracked plastics — anything from rugged tool cases to the abundance of plastic adorning modern vehicles — and give a fresh lease on life to once-broken items.

These things look seriously neat.

But I had questions:

  • Do they actually work?
  • Will my humble abode be reduced to ashes?
  • Will the space ray gun tool give me an electric shock?
  • Does melting metal staples into plastic unleash a torrent of noxious fumes?

There was only one way to unravel these mysteries — I had to take the plunge and buy one. 

150W Plastic Welder Kit, 600 pieces

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150W Plastic Welder Kit

The 600-piece kit comes with a hot stapler soldering gun and a bounty of welding rods for fast repairs.

For the money, you get the welder — which looks like a ray gun — a load of different metal staples, cutters, an array of different plastic rods to use as filler material for the cracks, and a tool to melt the rods into the plastic cracks.

Yes, it looks like a ray gun

Yes, it looks like a ray gun.

Adrian Kingsley-Hughes/ZDNET

I have to admit that my expectations were low. There's a lot of junk out there, and tools advertised heavily on social media usually fall into this category.

As soon as the tool arrived, I set to work testing it — since I have no shortage of broken plastic things. I kicked off with a low-stakes project, something where I didn't care if I made a mess of it — a broken carry case for an electric drill. I thought this would be good practice.

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The kit comes all packed chaotically in a plastic box. Just a glance told me that repacking this puzzle would be quite the feat. The instructions, rather cryptic in nature, weren't much help either.

There's a lot of stuff packed into a small box

There's a lot of stuff packed into the small box.

Adrian Kingsley-Hughes/ZDNET

But armed with the knowledge gleaned from countless videos, I was raring to tackle the challenge!

I decided to practice on this broken drill case

I decided to practice on this broken drill case.

Adrian Kingsley-Hughes/ZDNET

Using the tool is rather simple. You first fit a staple to the end of the welding gun, and then you press the trigger to heat up the staple. But be careful, the mold gets hot really fast!

The staples get HOT REALLY FASY

Whatever you do, do not touch the staple when it's heated.

Adrian Kingsley-Hughes/ZDNET

Then, let go of the trigger to turn off the heater and gently push the staple into the plastic across the crack. Once it's sealed into the plastic, pull the gun out to release the mold.

Cutting the staples

Once you've the staples are pressed down, you can use a plier to remove any excess materials. 

Adrian Kingsley-Hughes/ZDNET

Melting a plastic filling rod into the crack to give added strength

Melting a plastic filling rod into the crack to give added strength

Adrian Kingsley-Hughes/ZDNET

After melting some plastic filing on top of the staples for added strength, to my surprise, I was pleased with the result. Sure, the concoction looks like something out of Frankenstein's workshop, but it's a solid enough repair, and far better than the crack that was there previously!

It might not look neat, but it's a solid repair and far better than a crack!

It might not look neat, but it's a solid repair and far better than a crack!

Adrian Kingsley-Hughes/ZDNET

The takeaways

I learned quite a few things from using the TikTik-recommended welding tool. 

  1. First, you have to be careful when handling such tools! You're dealing with hot metal and molten plastic.
  2. Press the hot staples gently into the plastic, because you don't want to push them through the plastic you're trying to repair!
  3. There are a lot of different types of staples, so consult the manual to find out which to use for a specific job.
  4. It's a good idea to practice before using the tool on plastic that you care about.
  5. The process generates quite a lot of harsh fumes, so doing this indoors is not a smart idea (I'm not making that mistake again!)
  6. If I wanted a tidier finish, I'd also think about sanding down the repaired area with my Dremel to make everything look neater.
  7. I did worry that the welder posed some sort of shock risk, but my testing shows it to be electrically safe.

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Overall, I'm very pleased with the plastic welder, and it exceeded my expectations. I can see this being really useful for all sorts of cracked and broken plastic — from things like the trim or underbody bits of plastic on cars to carry cases and other household items.

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